(1) Field of the Invention
This invention pertains to the field of fiber optics and optical data transmission. More particularly, this invention pertains to the use of Bragg gratings to code or label optical conduits with unique multi-digit identification numbers or codes that can be read by light from any point along such optical conduits. The identification codes facilitate rapid identification optical conduits.
(2) Background
When servicing data transmission cables, one is often required to be able to distinguish data conduits from each other. In the case of electrical data transmission conduits, it is known to utilize unique resistors attached along such conduits to serve as identification markers or labels. This allows service personnel to identify a particular conduit from other adjacent conduits by simply passing an electrical current along the conduit. However, optical data conduits are not amenable to such use of electrical resistors as markers. Thus, distinguishing optical conduits from each other remains a difficult task.
It is known that an optical time domain reflectometer can be used to identify the time domain reflection signature of light pulses transmitted along an optical conduit. Because each optical coupling and other imperfections along an optical conduit create a reflection, each optical conduit generally has a unique reflection signature. However, without prior knowledge of the reflection signature of a particular optical conduit, the optical conduit can not be identified simply by measuring its reflection signature. Moreover, as an optical conduit is repaired or otherwise altered, its reflection signature changes.
The inventor of the present invention has appreciated the desirability of a method capable of quickly identifying a particular optical conduit from amongst other optical conduits, from any location along the optical conduit. For example, in a situation where a cable of numerous optical conduits has been severed, the inventor appreciates that is desirable to quickly identify the separate portions of a particular conduit that should be rejoined, without needing specific familiarity with the cable or the particular optical conduit. The present inventions achieves these desired results and provides other advantages.